Dishwashing apparatus



March 6, 1962 .1. L. MIXON 3,023,757

DISHWASHING APPARATUS Filed May 6, 1960 INVENTOR JOSEPH, L- MIXONATTORNEY United States Patent 3,023,757 DISHWASHING APPARATUS Joseph L.Mixon, Columbus, Ohio, assignor to Westinghouse Electric Corporation,East Pittsburgh, Pa., a corporation of Pennsylvania Filed May 6, 1960,Ser. No. 27,371 1 Claim. (Cl. 134-99) This invention relates todishwashing apparatus, especially domestic dishwashers used in the homefor washing and drying dishes, and more particularly to improved meansfor drying dishes and the like with air currents after they have beenwashed and rinsed.

Domestic dishwashers usually have a washing chamber or vat with a sumpformed at the bottom thereof to hold the liquid used for washing andrinsing the dishes. Generally, liquid is sprayed on the dishes either bya bladed impeller mounted in the sump or by a tubular distributormounted for rotation in a central region of the washing chamber.Dishwashers using the bladed impeller have an advantage in that theimpeller may be employed during the drying cycle, after liquid has beenevacuated from the sump, to promote the dispersed flow of air throughthe vat for drying dishes. On the other hand, a centrally located liquiddistributor is thought to obtain improved washing action because lesssoil is redeposited on the dishes. However, one disadvantage of thelatter type of dishwasher is that the distributor is incapable of movingair over the dishes during the drying cycle; and, although it ispossible to add a blower for this purpose, the cost thereof is a seriousdrawback. Despite this disadvantage, dishwashers employing a centrallylocated water distributor are now in common use because they are wellsuited to the currently popular, frontopening kind of dishwasher. Thisinvention copes with the problem of providing a dispersed flow of air bynatural air currents through the dishwasher vat in order to dry dishesat a uniform rate, without the use of a blower.

Apparatus embodying the invention includes a cabinet provided interiorlywith a washing chamber and an apparatus compartment. Dishes are held inthe washing chamber by dish storage racks, preferably two, arranged oneabove the other. Communication between the apparatus compartment and thewashing chamber is provided by means of wall structure in which isformed an opening. Extending through the opening is a conduit forconveying liquid to the washing chamber, and which has an end portionprojecting into the washing chamber beyond the wall structure. Alsoprovided is a collar which includes a tubular portion arranged in spacedrelation to the wall structure, and which further includes an annularflange connected between the tubular portion of the collar and the endportion of the conduit. The conduit, the wall structure, and the collarare respectively received one within the next to define a sinuous airpassageway between the apparatus compartment and the washing chamber,and thus prevents liquid splashed about the washing chamber during thewashing or rinsing cycles from entering the apparatus compartmentthrough the air passageway.

The present arrangement provides for the introduction of air to the vatfrom the same general region in which liquid is introduced to thewashing chamber, preferably through a central region of the sump so thatthe air has an opportunity to come into contact with all of the dishesbefore it exits from the vat. An electrical resistance heater isprovided in a lower portion of the washing chamber, below the lower dishstorage rack, to heat the air introduced and to promote the flow of airover the dishes and through the washing chamber.

The various objects, features and advantages of the Patented Mar. 6,1962 present invention will appear more fully from the detaileddescription which follows, taken in connection with the accompanyingdrawing, forming a part of this application, in which:

FIG. 1 is a view, partly in vertical section and partly in elevation, ofa domestic dishwasher, as viewed from the side, constructed and arrangedaccording to the invention; and

FIG. 2 is a horizontal sectional view of the dishwasher of FIG. 1, takenalong line II-II of FIG. 1.

The invention, as shown, is applied to a domestic dishwasher of thefront-opening type which includes a box-like cabinet 10. A vat 11,defining a washing chamber, is disposed within an upper portion of thecabinet 10 and has a bottom wall 12 which slopes downwardly and inwardlyto define a sump 13 for liquid serving as a washing and/ or rinsingagent. The bottom wall 12 also partitions the vat 11 from an apparatuscompartment 14 which houses a liquid return and pumping system, as wellas apparatus for admitting and discharging liquid, in the lower portionof the cabinet 10.

A conventional access opening to vat 11 is formed in a front wall of thecabinet 10 and is closed by a hingeably mounted door 16, movable to anopen, horizontal position below the access opening.

Within the vat 11 upper and lower dish storage racks 17 and 18,respectively, are suitably supported for rolling horizontal movement.The racks 17 and 18 are preferably oi open-work construction and aremovable into and out of the vat through the access opening forconvenient loading and unloading of dishes.

The apparatus compartment 14 houses a pump 21 which is driven by anelectric motor (not shown) and has its inlet connected to the sump 13,and its outlet connected to a conduit 23 which delivers liquid to thevat 11. The conduit 23 extends upwardly and enters the vat '11 throughan opening or passageway in the sump 13 defined by upstanding, tubularwall structure 25. The latter may be formed integrally with t e bottomwall 12, it projects into the vat 11 beyond the sump 13, and the opening'it defines provides communication between the vat 11 and the apparatuscompartment 14. A rotatable water distributor 2d of the type shown inFIG. 1 of the drawing is employed for receiving and projecting theentire output of the pump 21 toward dishes or other articles stored onthe racks 17 and 18. The distributor 26 has an entrance opening formedin its base for admitting water thereto from the conduit 23. Preferablythe distributor 26 is supported in a central region of the vat 11 byportions of the lower rack 18 and is movable therewith into and out ofthe vat. Although, various kinds of distributors may be used with thisinvention, reference is made to the copending application of Anthony B.Marmo and Vinal D. Thurston, Serial No. 680,461, filed August 27, 1957,and assigned to the assignee of the present invention, for a detaileddescription of the liquid distributor shown in FIG. 1.

Referring again to the pump outlet conduit 23 which extends verticallyupwardly through the sump opening, this part is preferably in spacedrelationship to the tubular wall structure 25, and it has an end portionprojecting into the vat 11 beyond the wall structure 25. The inner orupper ends of the conduit 23 and the wall structure 25 are above thelevel of the maximum quantity of liquid present in the vat at any time.At or near the upper end portion of the conduit 23 is secured a collar29. The latter includes an annular baflie or flange 31; by which thecollar 29 is secured to conduit 23, and which extends horizontally, ortransversely, of the conduit so as to overlie the opening defined by thetubular wall structure 25. The collar 29 also includes a tubular member32 depending from the flange 30, and which extends downwardly towardsump 13, in overlapping and surrounding relationship with the tubularwall structure 25. The conduit 23, the Wall structure 25, and the collar29 are respectively received in spaced relationship one within the nextto define a sinuous air duct or passageway 34 between the compartment 14and the vat 11.

Air leaving compartment 14 first flows upwardly through the regionbetween the tubular wall structure 25 and the conduit 23, next outwardlyunder collar flange 3i), and then downwardly in the region betweenconduit 23 and the tubular member 32 of collar 29 before entering thevat 11. The flange 30 of collar 29 is preferably imperforate so as toprovide an umbrella which shelters the duct 34 and prevents liquidsplashed about vat 11 during the washing and rinsing cycles fromentering the apparatus compartment 14.

An electrical resistance heating element 36 is mounted in the vat 11 atthe outlet of the air duct 34 to heat and promote the flow of air overthe dishes and through the vat 11 when no liquid is present in the vat.For this purpose, the heating element 36 surrounds the wall structure 25and the adjacent outlet of the duct 34, in spaced relationship with thecollar 32 and the bottom wall 12; and it lies below the lower rack 18,in a region usually occupied by liquid when the sump 13 is filled withwater during the wash and rinse cycles. During the drying cycle, whenthe vat 11 is devoid of liquid, air enters the vat from the duct 34, itis heated by the heating element 36, and then rises in the vat. The airduct 34 is located in a lower central region of the vat 11 and, sinceair flows radially outwardly and upwardly from the duct 34, the inducedflow of heated air is well dispersed throughout the vat 11 as it movesupwardly, therefore drying dishes and other articles stored on the racks17 and 18 at a fairly uniform rate.

The heating element 36 may also be used during the washing cycle, or therinsing cycle, or both, to maintain the liquid in the sump 13 at a givenminimum temperature, say 140 F.

In a lower front portion of the cabinet louvered openings 38 to theapparatus compartment 14 are provided to admit. fresh air. The cabinet10 is also provided with bafiied apertures 40 in the upper portion ofthe door 16.

Unlike prior art arrangements which require a blower to promote theuniform distribution of air for drying dishes, the present arrangementutilizes a heating element to promote circulation of drying air throughthe vat.

While the invention has been shown in but one form, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various changes and modifications without departing fromthe spirit thereof.

What is claimed is:

Dishwashing apparatus including a cabinet having a wall portion thereindividing the interior of said cabinet into a washing chamber above saidwall portion and an apparatus compartment below said wall portion, saidcabinet being provided with an air outlet opening in an upper region ofsaid washing chamber and an air inlet opening in said apparatusompartment, said wall portion having a sump formed therein forcontaining liquid and upstanding tubular wall structure which projectsinto said washing chamber beyond said sump and defines an openingproviding communication between said chamber and said compartment; rackmeans in said washing chamber for holding dishes; a stationary conduitfor conveying liquid to said Washing chamber extendng upwardly throughsaid opening and including an end portion which projects into saidwashing chamber beyond said wall structure; a liquid distributor mountedin said washing chamber in liquid receiving relationship with saidconduit for receiving liquid therefrom and projecting it about saidwashing chamber; a pump disposed in said apparatus compartment forsupplying liquid to said distributor through said conduit; a collarhaving a tubular portion surrounding said wall structure in spacedrelationship, and an annular flange secured between said tubular portionand the end portion of said conduit; said conduit, said wall structure,and said collar being respectively received one within the next todefine a sinuous air duct between said apparatus compartment and saidwashing chamber which is sheltered from liquid by said collar, and aheating element in said washing chamber below said rack means to heatand promote a flow of air from said inlet, through said air duct andwashing chamber, and out said outlet.

Flannery Feb. 7, 1956 Marmo et al. July 5, 1960

